Insecticidal repellent



United States Patent Office 2,971,881 Patented Feb. 14, 1961 2,971,881 INSECTICIDAL REPELLENT Willis Nels Bruce, Champaign, 111., assignor to Lee Rainer, Miami Beach, Fla.

Claims. (Cl. 16722) This application is a division of my copending application, Serial No. 712,333 filed January 31, 1958.

This invention relates to an insect control composition and has more particular reference to a combination of insecticide and insect repellent for protection against insects.

In my copending application, Serial No. 570,696, filed March 12, 1956, now Patent No. 2,937,969, entitled Fly Repellent, I have disclosed as the active ingredient of a novel insect repellent di-n-butyl succinate and other npropyl and n-butyl diesters of maleic, fumaric, and succinic acids, all having the desired repellent characteristics and persistence. That application is directed to the combination of such repellents with certain "materials among which may be mentioned piperonyl butoxide, isosafrole, and various unsaturated fatty acids and fatty acid esters, which exert a synergistic effect upon the repellents.

I have discovered that combinations of those repellents with certain insecticides, such combinations being here inafter sometimes called insecticidal repellents, produce a synerg stic interaction providing not only relatively rapid insecticidal action with a residual repellency surviving such action, but also repellency and toxicity in the combination which are substantially greater, respectively, than the repellency of the repellent and knockdown properties of the insecticide combined therewith when used separately.

I have found that any of Thanite (iso-bornyl thiocyanoacetate), Lethane 384 (B-butoxy, B-thiocyano diethyl ether), or other thiocyanate insecticides when combined with the repellent, result in an insecticidal repellent having the advantageous interaction between the repellent and insecticide and, to a greater 'or lesser degree, the stabilizing effect just mentioned above.

An object'of the invention is the provision of a novel insecticidal repellent which is of great value in protecting cattle, horses, hogs, and other animals from insect attack. It is also exceedingly useful in the home in reon dairy animals or in dairy barns is highly restricted because of danger to the animal itself or because of the possibility of the insecticide being transmitted into the cows milk and so to the consumer.- The use of certain insecticides is likewise hazardous in conjunction with meat animals in that the meat derived therefrom may carry insecticidal residues to the human consumer.

A further object of the invention is the provision of an insecticidal repellent wherein a substantially smaller quantity of insecticide is required for the performance of a desired insecticidal function and the chance, therefore, of danger to the animal or to the human consumer is greatly diminished. The approved insecticides may therefore be used without painstaking control of quantity, and the prospects of other more hazardous insecticide being approved for use on animals are good. 1

e Other objects and advantages of my invention will be apparent from the following description thereof, and the invention consists in the combination of one or more of the above-identified repellents with one or more of the above-identified insecticides to provide an insecticidal repellent which has greater repellency or knock-down properties than the same quantities of the repellent and insecticide in the insecticidal repellent respectively have when used alone.

As will be understood by those skilled in the art, the effectiveness of an insecticide or repellent depends on the amount or concentration of active material deposited on a given area or, in other words, on the quantity which a fly or other insect will encounter on a cow or in a barn,

. or in a house.

ducing the number of house flies, mosquitoes, cockroaches, ants, Silverfish, and other annoying insects.

The invention is also useful in the preservation of stored grain and other products subject to insect damage in storage. The novel insecticidal repellent is exceedingly efiective in controlling insects in barns and other buildings where flies and the like breed profusely and prove highly annoying and from-which dirt, contamination, and disease are spread. In short, the composition prepared in accordance with my invention may be employed in any situation where insecticides or repellents are now used.

Another object of the invention is the provision of an insecticidal repellent wherein certain insecticides contained in a composition prepared in accordance with my invention, are now useful Where such insecticides alone are dangerous.

The use of certain exceedingly efiective insecticides is dangerous or forbidden for many purposes. For instance, the list of insecticides permitted for the control of flies may be further diluted from about The novel composition is prepared preferably as a solution or mixture of the repellent and insecticide in or with a suitable vehicle, carrier, or diluent. The proportions employed are such as to leave on the treated surface the desired amount or concentration'of the insecticidal repellent when the directions for-application of theinsecticiderepellent solution have been followed. Specimen solu'- tions are, for back rubbers and oil spray concentrate, about-20% insecticidal repellent and No. 9oil, kerosene, or other suitable mineral or vegetable'oihfor an oil spray solution, I employ 0.5% combined insecticide andrepellent and the'balanc'e, No. 9 oil or the above stated equivalent thereof. In the event it is desired to make an oil spray from the concentrate, the'concentrate 20 to about 40 times An appropriate emulof combined insecticide of Atlox 1045A (polywith No. 9 oil or its equivalent. sion concentrate is about 20% and repellent and about 10% oxyethylene sorbitol esters of mixed oleic and lauric acids) or other emulsifier, and balance No. 9 oil. In use, the emulsion concentrate may be diluted from about 5 to about 40 times with water.

For the sake of brevity I have herein used the term synergism. While I believed this term is aptly employed in the description of my invention, the term potentiation of action has occurred to me as being less restrictive. It will be appreciated that the improved effectiveness of the novel composition may be attributable in part, at least, to the preservative efiect which the repellents exert on certain of the insecticides. Mere preservation or stability of the insecticide is not, however, adequate to account for the improved repellency or for the augmented knock-down effects of the composition when compared with the repellency of the repellent and the knock-down effects of the repellent and insecticide, respectively, when used alone. Another part, therefore, of the improved activity may be attributable to biological factors. Possibly the improved performance may be at tributable in part to still further factors of which I have no knowledge. The fact remains, however, that a co operative efliect is noticed between the insecticide and quantity of a stated impregnant in terms of milligrams per square foot. The efficacy of the impregnant then is measured in terms of the minutes taken to achieve 100% knock-down of the flies.

Repellency is determined by folding filter papers impregnated with the stated quantity of impregnant in terms of milligrams per square foot so as to form a free-standing shallow conical cup. Weighed lactose pellets are then placed in the bottom of each of the cups or inside the apex of the cone.

An exposure cage is provided with a horizontal turntable in it and a plurality of treated cups are deposited on the turntable about the rim thereof. Illumination and a source of water are likewise provided in the cage. Among the 'filter papers isincluded a check or control pellet in an untreated cup.

Flies are introduced into the cage on the basis of approximately 150 flies per cup. The turntable is rotated slowly. At the end of a measured period of time, or at about that time when the check or control pellet is totally consumed, the filter papers are withdrawn from the cage and the pellets remaining dried and weighed. Repellency is expressed as the percentage which the end weight of the pellet associated with any particular impregnant bears to the initial weight of the pellet.

In the following tables the term repellent refers to the n-butyl diester of succinic acid.

In the tables which follow, the two columns at the left headed R and I relate to the concentrations of repellent and insecticide, respectively, in terms of milligrams per square foot. The columns headed R and T under Percent repellency of indicate the percentage repellency of the repellent and insecticide, respectively, in the concentration given in the left-hand columns. The column headed Sum is the arithmetic total of the separate R and 1 columns. The column headed Combined R l-I gives the repellency of the combina tion of repellent and insecticide in the respective concentrations given in the left-hand columns. The R, I, and Combined R-l-I under Knock-down time give the same relative information as to the knock-down determinations in minutes.

TABLE 1 Repellent and "Thanite" [Exposed 6 hours to ultraviolet light at 33 0.]

Mgs./sq. it. Percent Bepellency oi- Knock-down time in minutes Com- Com- R I R I Sum bined R I bined R+I R+I 100 67 0 67 67 N 99 1 64 0 64 70 62 34 90 54 8 62 81 O 35 22 50 50 36 18 54 93 27 10 10 90 ll 35 46 88 N 22 12 2 98 0 42 42 84 14 0' 100 0 44 44 44 E 20 20 From the foregoing table, it vw'll be seen that while optimum repellency of 67% is achieved by the repellent alone at the concentration of 100 milligrams thereof per square foot, a combination of equal parts of repellent and Thanite achieves a repellency of 93%. Likewise, while the best knock-down time of 20 minutes is achieved by Thanite at 100 milligrams per square foot, the same equal combination achieves a knock-down time of 10 minutes. Acceptable results are achieved where Thanite makes up from about 0.5% to about 98% and the repellent makes up from about 99.5% to about 2% by weight of the combination, the presently preferred combination being about 25% of the repellent and about 75% for Thanite.

In all of the tables above the least combination tested at each end of the proportionate scales shows an improvement of performance both as to repellency at the dominant repellent end of the scale and as to knock-down at the dominant insecticide end of the scale, and as the insecticidal repellent approaches the center of the scales generally, the improvement becomes more marked and significant. The increased efiiciency in both respects, it will be recalled, is over and above the additive efiects of the components determined separately. I term this region between the added effects of the separate components and the effects of the combination the area of synergism.

Table 2 shows various compositions of the novel insecticidal repellent using Lethane 384 as the insecticide and the effectiveness of each of those compositions.

TABLE 2 Percent Knock- Formula MgsJsq. Time aged in Repeldown ft. Ultraviolet lency Time in Minutes 100 4 hrs. 29 C 93 None 99 4 hrs. 29 C 91 None 1 4 hrs. 29 C 0 None 99 and 1 4 hrs. 29 C..--- 99 48 pe 90 4 hrs. 29 0..... 86 None Lethane 384 10 4 hrs. 29 C..... 6 22 Combined.-. 90 and 10 4hrs. 29 C... 97 Y 12 Repellent l0 4 hrs. 29 0..... 11 l\one "Lethane 384... 90 4 hrs. 29 0.... 29 11 Combined 10 and 90 4 hrs. 29 C... 67 4 It will be appreciated from the foregoing table that the repellency of the combinations is materially improved over thatof the components in all cases.

As seen in Table 2, from about 1% to about 90% by weight of Lethane 384 with the balance repellent produces a combination demonstrating synergistic effects, however a composition of about 80% Lethane 384 and about 20% repellent is preferred.

It will be apparent from the foregoing description that the combination of repellents of the character here involved together with the above disclosed insecticides gives altogether unsuspected and unforeseen results in augmenting the repellency of the repellent and the toxicity of the insecticide and maintaing the effectiveness of the'components in both respects over a substantially prolonged period of time. The economic consequences of my invention are important. Protection against insect attack for animals, households, stored grains,-persons, etc., is more easily, more'elfectively, and more permanently achieved at lower cost. This protection is achieved with greater safety in that the enhanced eflectiveness of the insecticidal components which are in many cases toxic to some degree to animals and humans, makes possible the use of materially reduced quantities thereof. Of all the tested insecticides in combination with the repellent, I have found the repellency and, in a great majority of instances, the insecticidal effectiveness as well to be greatly improved- It is thought that the invention and its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the composition and ingredients thereof without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the forms hereinbefore described being merely preferred embodiments thereof.

I claim.

1. An insecticidal repellent comprising a combination of from about 1% to about 98% by weight of di-n-butyl succinate and from about 2% to about 99% by weight of a thiocyanate insecticide selected from the group consisting of iso-bornyl thiocyanate and B-butoxy, B-thiocyano diethyl ether.

2. An insecticidal repellent composition comprising a conbination of di-n-butyl succinate and B-butoxy, B- thiocyano diethyl ether wherein said succinate makes up from about 99% to about 10% and said B-butoxy, B- th ocyano diethyl ether makes up from about 1% to about 90% by weight of said combination.

3. An insecticidal repellent solution comprising a combination of di-n-butyl succinate and B-butoxy, B-thiocyano diethyl ether wherein said succinate makes up about 20% and said B-butoxy, B-thiocyano diethyl ether makes up about 80% by weight of said combination.

4. An insecticidal repellent composition comprising a combination of di-n-butyl succinate and iso-bornyl thiocyanoacetate wherein said succinate makes up from about 99% to about 2% and said iso-bornyl thiocyanoacetate makes up from about 1% to about 98% by weight of said combination.

5. An insecticidal repellent solution comprising a combination of di-n-butyl succinate and iso-bornyl thiocyanoacetate wherein said succinate makes up about 25% and said iso-bornyl thiocyanoacetate makes up about 75% by weight of said combination.

References Cited in the file of this patent King: US. Dept. Agr. Handbook No. 69, May 1954, pp. 316, 323.

Hanna: Handbook of Agr. Chem., 2nd. ed., 1958, p. 335.

Smith: J. Eco. But. 42, June 1949, pp. 439-440. 

1. AN INSECTICIDAL REPELLENT COMPRISING A COMBINATION OF FROM ABOUT 1% TO ABOUT 98% BY WEIGHT OF DI-N-BUTYL SUCCINATE AND FROM ABOUT 2% TO ABOUT 99% BY WEIGHT OF A THIOCYANATE INSECTICIDE SELECTED FROM THE GROUP CONSISTING OF ISO-BORNYL THIOCYANATE AND B-BUTOXY, B-THIOCYANO DIETHYL ETHER. 